How to model complex tubular forms in Archicad

[Anonymous]

Here's an example rendering of what I'm trying to model:

[Steve Jepson]

Make a Complex Profile for the Tube. It's will be a Wall you can use to follow any path you can defile. The advantage of starting out with the tube as a wall is that you could put windows in it. Later, you might want to turn that into a morph so you can edit it with more rounded openings and such.

Personally I would model it one part at a time with parts that are as close as possible to the actual components it will be constructed with.

[Anonymous]

Yes i did that, but the problem is that the path it has to follow grows wider in certain parts and I cant get de wall to get wider in that part.

[Steve Jepson]

You stretch the tube for something like that after you turn it into a morph.

Here is the thing to keep in mind.

ArchiCAD is not a free-from modeling program. The strong suit and purpose of ArchiCAD ( if you ask me) is that it is a program for turning free-form designs in to something that is actually constructable, documentable, dimensionable, and manufacturable.
(sorry for using so many non-words)

There is no such thing as free-form in a building unless your making a mud hut, and if you are, you probably don't need Plans for it anyway.

No matter how free-form the appearance of the structure is, at some point it has be assembled/constructed out of manufactured parts. How to take the surfaces and structural components of someones Blobitecture and document it's geometry (make Plans for manufacturing/constructing it) is what ArchiCAD does better than any program I know of.

Graphisoft would probably disagree with me, as will many ArchiCAD users, but my opinion is that Construction Documentation/Plans for Buildlings is the primary function of ArchiCAD.

To me, this is why we have only a small need for free-form modeling in ArchiCAD. It's real purpose is the exact opposite of free-form. It is a tool for eliminating that completely.

There is no such thing as free-form components in a building/structure made of manufactured components.

For the Architect that wants to design something that is visually a flowing, curving, free-form, etc... ArchiCAD is not the right program for that.

But when it comes time to turn that ridiculous free-form blob into something you can actually build, that is when you need ArchiCAD.

The pseudo free-form modeling tools we have in ArchiCAD are there to assist us in that process. Now if your using these tools ( Morphs/Shells) for the purpose of creating some sort of free-form model, you will be disappointed by how nearly impossible it is to actually make what you want. I find the Morph and Shell tools very difficult to use.

If you can define the geometry of your building components it can be modeled with ArchiCAD. Also, if you need to use ArchiCAD as a tool to help you define the geometry of your components, ArchiCAD is a really good tool for that too.

If all you want to do is free-form model a building of some kind, ArchiCAD is not the best tool for the job.

That being said, I have yet to come across something for a building that I could not model with ArchiCAD, and in a way that I can make the necessary Plans to construction/fabrication it.

[Steve Jepson]

vjdonoso wrote:
Yes i did that, but the problem is that the path it has to follow grows wider in certain parts and I cant get de wall to get wider in that part.

Your not ready to model the main tube until those curves are dimensioned, perhaps some hot spots for reference, points of origin, etc...
If your just making some whimsical free-from variation of the bridge then ArchiCAD is not a very good tool for that.

Also, a tube like your describing with a continuously curving and changing oval is just plain stupid ( in my opinion only that is ). I am not interested in showing you how to model something like that. And if I did, it would not be based the methods of free-form modeling. It would be based on the idea that three is no such thing as free-form.

I could show you how to model and document building skins ( glass or metal clad panels) for a building shaped like a pile of bubbles if it were for the purpose of making an actual structure.

If you can get a model of an continuously smooth curving oval that is continuously changing in diameter with ArchiCAD it would be the result of deforming something. When you deform something like a morph or shell, you will need other objects that provide the snap points and limits. Otherwise, it will be nearly impossible to get what you want in ArchiCAD.

[Anonymous]

Graphisoft would probably disagree with me, as will many ArchiCAD users, but my opinion is that Construction Documentation/Plans for Buildlings is the primary function of ArchiCAD.

I agree with you on this point completely. This is how I earn my living - getting the documents out the door on time.

[Steve Jepson]

http://urbantoronto.ca/news/2011/07/breaking-renderings-new-bridge-cityplace-front-street-west






http://www.arcspace.com/features/dominique-perrault/arganzuela-footbridge/












.

[Steve Jepson]

This is a rational design. No free-form. And so it can be modeled with precision in ArchiCAD. Imagine now if it the tapered cones were not uniform and were following a curved path.
That is what I think you are wanting to do. Your wanting to take something rational and constructable and make it painfully unsystematic for the sake of art.

When the geometry for your bridge is defined and modeled with (Inventor,SolidWorks, 3DS, Rhino, C4D... then you can import the free-form model and go to work on it with ArchiCAD and transform it into working drawings.

http://www.arcspace.com/features/dominique-perrault/arganzuela-footbridge/

[Anonymous]

Yes Steve, I modeled the complex tubular form in autocad using the loft tool, now I have to rationalize the cilinder and start making the construction elements. The first Thing I did was define a structural grid, im thinking of making curved beams that divide en 4 partes 2 for the top of the walkway and 2 for de bottom part

[Steve Jepson]

If you have AutoCAD then the Sweep tool might be the best way to extrude an oval along a curved path, where the tube/oval is larger in some places.

Do you have the geometry you want into ArchiCAD yet? From there you can put a surface on it with the morph tool. Make it thin, and make it glass so you can see through it. It will provide boundaries for you to work with. It can be used with Solid Elements Operations to trim/form things to that shape.

[Steve Jepson]

. the temporary oval/tube would be used in sections, cutaways, etc...to find the precise limits of the framing. And also for any cladding for glass surfaces you might need.